Safety device for circuitous elevators



Aug. 2, 1932'. G. CURRIE SAFETY DEVICE FOR G'IRCUITOUS ELEVATORS 2Sheets-Sheet l Filed Jan. 30, 1951 INVENTOR Gi/fiB/f Cliff/e ATTORNEYAug. 2, 1932. G] CURRIE 1,869,883

SAFETY DEVICE FOR CI RCUITOUS ELEVATORS Filed Jan. 80, 1951- 2Sheets-Sheet 2 WITNESSES INVENTOR Gi/bP/f Currie 4% W I BY 7 A:|'TORNEYPatented Aug. 2, 1932 GILBERT CUREIE, OF FOREST HILLS PENNSYLVANIA,ASSIGrNOE .TO WESTINGHOUSE ELECTRIC 6: MANUFACTURING COMPANY, ACORPORATION OF PENNSYLVANIA SAFETY DEVIiCI E FOR CIRCUITOUS ELEVATORSApplication 1118a January 30,1931. ,Serial No. 512,290;

My invention relates to safety devices for circuitous elevators andrelates particularly to safety devices applied to circuitous elevatorshaving two or more endless chains supporting and moving a plurality ofreceptacles in an endless path, for the purpose of preventing relativemovement of the endless chains.

As a solution to the problem of parking g automobiles in congested areasof large cities,

circuitous elevators have been proposed. The term circuitous elevator isapplied herein to a conveyor structure of any type in which a pluralityof receptacles for supporting loads are movable in an endless path. Onetype of circuitous elevator for storing automobiles, which has beenproposed, is (1.6? scribed in detail in the copending application ofHenry D. James and Gilbert Currie, Serial No. 512,291, filed Jan. 30,1931 and assigned to Westinghouse Electric & Manufacturing Company, andmy invention is illustrated as applied thereto,-although it should'beunderstood that it may be readily applied to a circuitous elevator ofany type or a conveyor or other device having a plurality of elementsnormally movable in synchronism, for the purpose of stopping all'of theelements if undesirable relative 0 movement occurs between them. Incircuitous elevators of the type described in the above-mentionedcopending application of Henry D. James and Gilbert Currie, as well asother similar types where- I in a pluralityof load receptacles arepivotally suspended from and between a pair of endless flexible membersor chains which are disposed vertically in parallel spaced relation andsimultaneously movable in similar paths to move the receptacles in anendless path, it is possiblefor an accident to occur which permits orcauses the endless chains to move relatively. In the event of suchoccurrence, the load receptacles will be so that loads positionedthereon will be displaced and seriously injured. I

Likewise, serious damage to the elevator structure itself may occur inthe event of relative movement of the endless chains. For

distorted, or, at least, abnormally oriented,

example, in the event that the sheaves or sprocket wheels supporting theendless chains at their lower ends are keyed to a common shaft, relativemovement of the endless chains will cause a torsion of the shaft and aconsequent injury to the elevator structure, thus rendering the elevatorinoperative for an indefinite period and causing loss of income to theowner, as well as inconvenience and annoyance to the patrons. Y i 1 Inorder to prevent such consequences, as the result of the relativemovement of the endless chains of a circuit elevator, I have provided ameans for preventing such movement.

It is an object of my invention, therefore, to stop the movement of twoor more mem bers, which are designed to move normally in synchronismupon relative movement storage structure, a portion being broken away toshow the application of my invention to the circuitous elevatorrepresented in Fig. 3 is an enlarged view, in side elevation, of asheave or sprocket wheel for supporting an endless chain of a circuitouselevator and the method of attaching one of the commutators, comprisingmy invention, thereto.

' Fig. 4 is a sectional view, taken on line IVIV of Fig. 3, showing themethod of establishing an electrical connection to a commutator attachedto a sprocket wheel.

*ig. 5 is an enlarged view, in front eleva tion, of a contact finger orbrush holder which I employ to establish an electrical connection to acommutator.

Fig. 6 is a side view of the brush holder shown in Fig. 5.

Fig. 7 is a View corresponding to that of Fig. 5 but having the contactfingers removed and showing the slots for effecting adjustment of theposition of the contact fingers.

Fig. 8 is a simplified control diagram illustrating, in part, the methodof connecting the contact fingers engaging the commutators in a controlcircuit for the motor employed to drive the circuitous elevator.

Referring to Fig. 1, the circuitous elevator, to which my invention isherein specifically applied, comprises a building structure 11constructed in a usual manner and having a plurality of slings, cages orreceptacles 12 pivotally suspended at regular intervals from and betweena pair of endless chains 13 and 14, disposed vertically in parallelspaced relation, and movable therewith in an endless path within thestructure 11. I

The endless chains are supported, in vertically displaced relation, bysuitable sheaves or sprocket wheels 15 at top and bottom. Each of thesheaves 15 is keyed to a stub shaft 16 which is supported at the endsthereof on opposite sides of the sheave by suitable bearing members 17suspended from, or otherwise suitably attached to, horizontally disposedstructural members 18 which are attached, as by welding, to channel bars19 disposed around the vertically extending por tions of the endlesschains to maintain them in a fixed path of movement. The channel bars 19are supported upon a pedestal comprising four structural columns 20,disposed at the corners of the building structure 11, and a pair ofhorizontally disposed structural members 21 each supported by twocolumns in parallel relation.

The two spaced members 21 are disposed parallel to the front of thebuilding structure 11, and a horizontally-disposed structural member 22is supported, at its ends, by the members 21, in such position that thereceptacles 12 may pass freely thereby. The channel bars 19 aresupported upon the member 22 by means of horizontally disposedstructural members 23 which are rigidly attached to the channel barsassociated with acent vertically-extending portions of the same endlesschain.

The upper portions of the channel bars 19 are maintained in fixed spacedrelation, in a manner similar to that described above, by means ofstructural members 2 1 and 25.

Vertically-extending structural members 26 are provided for supportingthe upper end of the supporting structure of the endless chains toprevent lateral movement thereof with respect to the building structure11. The members 26 are slidabl y secured to the building structure topermit upward movement of the chain-supporting structure caused byexpansion resulting from temperature changes.

Each of the cages 12 is attached to the end less chains by means ofpairs of angularly disposed bracket arms 27 which pivotally engage theends of a receptacle. As indicated in Figs. 1 and 2, one pair of bracketarms 27 engages a trunnion disposed adjacent to the bottom edge of oneend of a receptacle, and a second pair engages a trunnion disposedadjacent to the upper edge of the receptacle at the opposite endthereof. A construction of this character minimizes objectionableswaying and swinging of the receptacles 12 during movement in theendless path.

Any suitable means may be provided for moving the receptaclessimultaneously. For purposes of illustration, I have provided a motor28, supported upon a platform attached to the channel bars 19, fordriving a pair of sprocket wheels29 and 30 which engage the adjacentvertically-extending portions of the endless chains 13 and 1 1,respectively. The sprocket wheels 29 and 30 are keyed or splined to acommon shaft 31 to which a gear wheel 32 is also keyed. The motor 28drives the gear wheel 32 through a speed-reducing gear mechanism 33.

A doorway 34, (Fig. 1) having suitable doors, is provided at the groundfloor level 35 for permitting the entrance and exit of automobiles toand from the receptacles 12.

The particular structure of the sling or receptacle is immaterial to mypresent invention, since any suitable support for automobiles may beprovided. The structure of the receptacles shown herein is described,however, in detail in the co-pending application of Henry D. James andGilbert Currie, above mentioned.

Referring to Figs. 3, 1 and 8, my present invention comprises a pair ofcommutators or T commutating rings 36 and 36 which are movablesynchronously at the same speed, with the movement of the endless chains13 and 14, respectively. Any suitable drive connection may be providedfor effecting the movement of the commutators 36 and 36. For purposes ofillustration, I have shown the commutator 36 suitably attached, as byscrews 37, to one of the sheaves or sprocket wheels 15, which engagesthe endless chain 13. The commutator 36 is similarly attached to asprocket wheel 15 which engages the endless chain 14. I have shown, inFig. 3, the commutator 36 only and have shown it as applied to a lowersprocket wheel 15, but it should be understood that the commutators maybe applied to sprocket wheels disposed at any desired location.

The commutators 36 and 36' are preferably of disc-shape disposedcoaxially with respect' to their associated sprocket Wheels.

Thecommutators may, however, be cylindrical and suitably secured to thesprocket wheels in any desired manner. "As illustrated, each commutatorcomprises an insulating base 3664 having a plurality of conductingsegments 38 and insulating segments39 radially disposed in alternaterelation in an annular groove in the insulatingbase; the width of '43,are disposed, preferably, on diametrically opposite sides of each of thecommutators 36 and 36.. The brackets maybe suitably supported by thestructural member 18, in

such position that the contact fingers 42 and 43 engage the segments ofthe commutators associated therewith." I

Referring more specifically to Figs. 5, 6 and 7, thebrackets 40 and 41are provided with spaced slots 44 forpermitting the adjustment of thecontact fingers 42 and 43 with respect to the commutators. Suitablebolts 45 and 4". one. of which may serve as an electrical terminal,extend through apertures in the contact fingers and, through the slot44, to secure the'fingers to the bracket 40 and 41.

The contact fingers of the bracket 40 are properly so adjusted in theirslots that, except for a short interval in transferring from conductingto insulating segments or vice versa, they both simultaneously engage aninsulating segment 3901 a conducting segment 38 at the time the contactfingers of the bracket 41, likewise properly adjusted, simultaneouslyengage a conducting segment 38 or an insulating segment 39.

The conducting segments 38 on the commutators are made preferablyslightly wider than the insulating segments 39, in order to insure that,at a certain instant during the disengagement of contact fingers from,and the engagement of contact fingers with,conducting or insulatingsegments, both pairs of contact fingers on brackets 40 and 41' shallsimultanenously engage conducting segments.

It understood that, if contact fingers having considerable contact areaare em ployed, the segments 38. and 39 maybe equal in width, because onepair of contact fingers will engage a conducting segment prior to thedisengagement of a conducting'segment by the other pair of contact.fingers associated with thesame commutator.

However, where contact fingers have a line-contact area, 1t 18exceedingly difficult to so'adjust the position thereof that,;

for either direction of rotation of the commutators, simultaneouscontact 'of the pair of contact fingers with different conductingsegments may be efiected. In order, there fore, to insure that, for bothdirections of rotation, this simultaneous engagement of the contactfingers with conducting segments of the same commutator shall occur, theconducting segments 38 on the commutators are made slightly wider thanthe insulating-segments. The required difference in width between theconductingand the insulating segments is very slight.

Although the brackets 40 and 41 are illustrated as being ondiametrically opposite sides of a commutator, it should be understoodthat any'other angular relation thereof, which efiects thesameresult,'is permissible.

Referring to Fig. 8, a method is shown for connecting the contactfingers associatedwith both of the commutators 36 and 36, so that anelectrical circuit is-maintained alternate ly first through the contactfingers on brackets 41 and conducting segments of thecommutators andthen through the contact mem here on brackets 40 and conductingsegmentsofthe commutators; there being a short transfer interval during whichall of the contact fingers are in engagement with conducting segments. 1I

By means of a connection such as described, an electrical circuit ismaintained through the contact fingers and the commutators as long astheendless chains 13and 14 move synchronously and atthe same speed. If aslight relative movement of the endless chains Band 14 occurs, thecircuit through the contact fingers and the commutators is interrupted.My invention is, in effect,

therefore, a switch which is normally closed I but which opens inresponse to a slight relative movement of the endless chains 13 and 14to effect the stopping of the movement thereof. v

I have not shown, in detail, a motor-control circuit in Fig. 8,since itis deemed unnecessary. My invention constitutes a. switch and it isreadily connected in any circuit for controlling the actuation of amotor; for example, in a circuit for energizingthe coils of directionrelays. I

The operation of my invention is best understood by an assumedoperation. it be assumed that the commutators 36 and 36, in Fig. 8, arerotating synchronously, at'the same speed, in accordance with themovement of the endless chains 18 and 14. respectively. At a particularinstant, under the conditions assumed, the commutators 36 and 36 occupyrelative positions, as shown in Fig. 8, in which the fingers 42 and 43engage the central portions of conducting and insulating segments of thecomniutators. At this particular instant, a circuit isestablished forpermitting the motor :28 to be energized, which circuit extends fromsupply conduct-or L1, through conductors 50 and 51, contact finger 43?),a conducting segment 38b of commutator .36, contact finger 42?), con.ductors 52, 53 and .54, contact finger 42a, a conducting segment 38a ofcommutator 36, contact finger 43a and conductors 55 and 56, to themotor-control circuit and thence to supply conductor L2 (not shown).

Let it be assumed that the endless chains 13 and '14 continue to movesimultaneously at the same speed, and that the commutators 36 and 36'are moved respectively in accordance with the movement thereof through adistance corresponding to the width. of a conducting segment 38. It willbe clear that, during the transfer of contact fingers from conducting toinsulating segments or vice versa, the contact fingers 42 and 43 of thebrackets 40 engage a conduct-ing segment 38 slightly before thedisengagement of a conducting segment 38 by the contact fingers 42 and43 on the brackets 41. After the commutators have rotated through adistance corresponding to the width of a segment 38, the contact fingers42a and 43a in Fig. 8 are in simultaneous engagement with an insulatingsegment 39a, and the contact fingers 42?) and 43?) are in simultaneousengagement with an insulating segment 39?). The circuit previouslytraced has, therefore, been interrupted, but another circuit wasestablished through contact members'420, 43c, 42d and 4365 prior to theinterruption of the circuit previously traced; the two circuits being inparallel. The circuit now extends from supply conductor L1, throughconductors 50 and 51, contact fingers 420, a conducting segment 38a oncommutator 36, contact finger 430, conductors 52, 53 and 54, contactfinger 43d, a conducting segment 386 on commutator 36, contact finger42d and conductors 55 and 56, to the supply conductor L2, as previouslydescribed.

Now let it be assumed that relative move ment of the chains 13 and 14occurs. In such case, a slight movement of the commutators 36 and 36 outof their relative positions, shown in Fig. 8, effects the interruptionof the circuits previously traced. If it be assumed that the commutator36 moves relatively to the commutator 36, so that the contact fingers42?) and 43b engage an insulating segment 39?) of the commutator 36' atthe same time that the contact fingers 42a and 43a engage a conductingsegment 38a of the commutator 36, the circuit previously tracedth'erethrough is opened, and de energization of the driving motor iseffected.

I Likewise, if :it be assumed that, upon small elative movement of theendless chains 13 and 14, the commutator-s 36 and 36 assume, at aparticular instant, such relative positions that the contact fingers 420and 430' are in engagement with a conducting segment 38a of thecommutator 36 at the same time the contact fingers 42?) and 436 are inengagement with an insulating segment 39% of the commutator 36, thecircuit previously traced therethrough is interrupted and thedeenergization of the motor 28 is efiected.

Although I have shown only two commutators movable in accordance withthe movement of two normally synchronously movable elements, it will beunderstood that more than two commutators may be employed, one for eachof a plurality of normally synchronously movable elements, together withcontact fingers associated with all of the commutators and connectedtogether in such manner' that, whenever relative movement between any ofthe movable elements occurs, the-movement of all of them is stopped. Itwill be further understood that my invention is applicable to devicesother than circuitous elevators or conveyors, in that it is applicableto any device or mechanism having a plurality of normally synchronouslymovable elements which must move in synchronism or not at all. g Itwill, therefore, be seen that I have pro-- vided a device for stoppingthe movement of two or more members, normally movable insynchr'onism,whenever relative movement between the members occurs. t will be seen,further, that I have provided a means for preventing serious injury to acircuitous elevator and to automobiles stored therein, should relativemovement of the conveyor members thereof occur.

t is understood that my invention is capable of various modificationswithout a departure from the spirit thereof. I desire, therefore, thatonly such limitations shall be imposed thereon as are necessitated bythe prior art and the scope of the appended claims.

I claim as my invention:

1. In a safety device for a conveyor including a plurality of endlessflexible members movable in similar endless paths, and motive means formoving said endless members, means responsive to relative movement ofthe endless members for stopping the movement thereof, said responsivemeans comprising a commutator for each of said endless members movablein accordance with the movement thereof, said commutators beingconstituted by a plurality of alternately spaced conducting andinsulating segments, and two pairs of stationarily disposed contactfingers for each of said commutators, one pair being disposed to beconnected by simultaneously engaging a conducting segment, while theother pair are separated by their simultaneous engagement with aninsulating segment, said contact fingers being connected to maintain aclosed circuit, whereby said motive means may be energized from a sourceofv energy supply when said endless flexible members move simultaneouslyat the same speed and to disconnect said motive means from the source ofsupply when said endless members move with respect to each other.

2. In a safety device for conveyors comprising a plurality of conveyorelements normally movable simultaneously at the same speed, means forstopping said conveyor elements upon relative movement thereof, saidmeans including a commutator for each conveyor element movable inaccordance with the movement thereof, each commutator having a pluralityof alternately disposed .conducting and insulating segments, and aplurality of contact members disposed in en gagement with saidcommutator segments and adapted to maintain an electrical circuit closedwhile said conveyor elements move simultaneously at the same speed andto interrupt the circuit when the conveyor elements move relatively.

3. In a conveyor, a plurality of conveyor elements movablesimultaneously at the same speed, and means for stopping said conveyorelements upon relative movement thereof, said means comprising acommutator for each conveyor element movable in accordance with themovement thereof, each commutator having a plurality of alternatelydisposed conducting and insulating segments, and a plurality of contactmembers for engaging said commutator segments and adapted to maintain anelectrical circuit closed while said conveyor elements movesimultaneously at the same speed and to interrupt the circuit when theconveyor elements move relatively.

4. In a conveyor, a plurality of conveyor elements movablesimultaneously at the same speed, motive means for moving said conveyorelements, and means for stopping said motive means upon relativemovement of the conveyor elements, said means comprising a commutatorfor each of said conveyor elements movable in accordance with themovement thereof, each commutator having a plurality of alternatelydisposed conducting and insulating segments, and acircuit forcontrolling said motive means including a plurality of contact membersdisposed in engagement with said commutator segments and adapted tomaintain a circuit closed while said conveyor elements movesimultaneously at the same speed and to interrupt the circuit whenrelative movement of the conveyor elements occurs.

In testimony whereof, I have hereunto subscribed my name this 22nd dayof January 1931. GILBERT CURRIE.

